From Ó Ceallacháin, named directly for Ceallachán Caisil, the tenth-century King of Munster — Cork chiefs of Duhallow and Clonmeen.
Gaelic Origin · Descendants of Ceallachán Caisil
Callaghan traces directly to Ceallachán Caisil, a tenth-century King of Munster whose reign is still remembered in the medieval saga Caithréim Cheallacháin Chaisil. His descendants, the Ó Ceallacháin, ruled Duhallow and Clonmeen in County Cork for generations after.
A name that reaches back to a named, verifiable king, in the same rare company as O'Brien's descent from Brian Boru.
Irish form: Ó Ceallacháin
